This invention relates to switches, and more particularly to reversible snap-action electrical switches.
In the electrical switch art, and particularly for relatively small, manually-operated switches, actuation solely by movement of the operator's hand can pose a number of problems. Moving the switch contacts at the same speed as the operator's hand can cause arcing between the contacts which could be avoided by a more rapid movement. In addition, the operator may move the switch control in a hesitating, unsteady manner, thereby producing additional arcing that could be avoided by a more positive motion.
Various snap-action switch designs have been employed in the past to produce a faster switching action and thereby minimize the above problems. In one approach separate actuating and switching members are connected by a lost motion coupling; the actuating member is manually advanced while the switching member is held in place until a point is reached at which it is released and snaps forward at an accelerated rate to produce a rapid switching.
The configuration of some of these switches is such that a snap-action motion occurs only when the switch contacts are moved from a first to a second state, and not when they are moved in the reverse direction back to the first state. In others, the switching member is successively snapped along a series of fixed positions, dwelling at each position until dislodged by a camming action from the actuating member.
While many of the above mechanisms do perform their intended function satisfactorily, there is still a need for a bidirectional snap-action switch which requires only a single dwelling location for the drive member. For example, the drive member may be interconnected with potentiometer units. In this case a snap-action motion may be desirable only at the beginning or end of the potentiometer resistance track.